ATIVIDADES ESPORTIVAS NA NATUREZA EM PORTO ALEGRE: DESAFIOS E OPORTUNIDADES

This study looked into the challenges and opportunities for developing outdoor sports in Porto Alegre, Brazil. Twenty-nine interviews were conducted with members of organizations working with the subjects as well as eight observations of groups of participants. The results indicated the challenges posed to selecting proper sites and measures to avoid overcrowding. Furthermore, the potential for involving participants, instructors and local communities in keeping the natural environment and in managing outdoor sports provide opportunities. In conclusion, this study demonstrated that outdoor sports must be avoided in some areas of the city. However, opportunities can mitigate the challenges through proactive management and promotion of outdoor sports. El objetivo de este estudio fue analizar los desafíos y oportunidades para el desarrollo de actividades deportivas en la naturaleza en Porto Alegre, Brasil. Se realizaron 29 entrevistas con representantes de organizaciones vinculadas a estas actividades, además de ocho observaciones de grupos que las practican. Los resultados indicaron que la selección de sitios apropiados para la realización de estas actividades y las medidas para evitar el hacinamiento de los locales de práctica representan desafíos, y que el potencial de compromiso de practicantes, instructores y comunidades locales en el mantenimiento del medio ambiente natural y en la gestión de actividades deportivas en la naturaleza representa oportunidades. En conclusión, el estudio demostró que estas actividades deben evitarse en algunas áreas de la ciudad. Sin embargo, a través de una gestión proactiva y de la promoción de actividades deportivas en la naturaleza las oportunidades pueden mitigar los desafíos. .Este estudo teve por objetivo analisar os desafios e as oportunidades para o desenvolvimento de atividades esportivas na natureza em Porto Alegre, Brasil. Foram realizadas 29 entrevistas com representantes de organizações ligadas a essas atividades e oito observações de grupos de praticantes. Os resultados indicaram que a escolha de locais apropriados para a realização dessas atividades e as medidas para evitar a superlotação dos locais de prática representam desafios; e o potencial de envolvimento de praticantes, instrutores e comunidades locais na manutenção do meio natural e na gestão de atividades esportivas na natureza representam oportunidades. Em conclusão, o estudo demonstrou que existem áreas da cidade em que essas atividades devem ser evitadas. No entanto, por meio de gerenciamento proativo e promoção de atividades esportivas na natureza, as oportunidades podem mitigar os desafios.

Effect of plain and carboxylated styrene-butadiene rubber on the rheological behavior of silica fume-class G Portland cement slurries

The incorpation of a high pozzolan content in cement systems enables an enhanced thermal stability. In an even harsh condition, where imposed deformations occur in addition to high temperatures, it is desirable that cementitious systems present high ductility, which can be achieved for example by adding polymers. The aim of this paper, is to better understand the rheological behavior of ductile cement slurries, designed for oil wells subjected to cyclic steam stimulation. The studied cement formulations contain Silica Fume and two different copolymers (Styrene-Butadiene and its carboxylated version). The influence of each copolymer content on the rheological parameters was investigated. Isothermal calorimetry was used to measure the induction period to guarantee that rheological parameters were carried out in the same hydration period. As the rheometer test was carried out in a non-isothermal condition together with a vane applied shear rate, increased reaction rates are expected. However, it is plausible to assume that the pastes remained in the induction period otherwise they would be in the acceleratory period where pastes start to set. Attempts have been made to correlate properties found by rheometry in the mini-slump test. It was observed that the XSBR delays and decreases the ettringite formation in the first hours of cement hydration, leading to lower yield stress values and increased viscosity and thixotropy. Good correlations were established between parameters measured by rheometry and mini-slump tests, which show promising results for potential use in on-site yield stress and plastic viscosity tests in Oil Well applications

Potential zoonotic sources of SARS‐CoV‐2 infections

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causing coronavirus disease-2019 (COVID-19) likely has evolutionary origins in other animals than humans based on genetically related viruses existing in rhinolophid bats and pangolins. Similar to other animal coronaviruses, SARS-CoV-2 contains a functional furin cleavage site in its spike protein, which may broaden the SARS-CoV-2 host range and affect pathogenesis. Whether ongoing zoonotic infections are possible in addition to efficient human-to-human transmission remains unclear. In contrast, human-to-animal transmission can occur based on evidence provided from natural and experimental settings. Carnivores, including domestic cats, ferrets and minks, appear to be particularly susceptible to SARS-CoV-2 in contrast to poultry and other animals reared as livestock such as cattle and swine. Epidemiologic evidence supported by genomic sequencing corroborated mink-to-human transmission events in farm settings. Airborne transmission of SARS-CoV-2 between experimentally infected cats additionally substantiates the possibility of cat-to-human transmission. To evaluate the COVID-19 risk represented by domestic and farmed carnivores, experimental assessments should include surveillance and health assessment of domestic and farmed carnivores, characterization of the immune interplay between SARS-CoV-2 and carnivore coronaviruses, determination of the SARS-CoV-2 host range beyond carnivores and identification of human risk groups such as veterinarians and farm workers. Strategies to mitigate the risk of zoonotic SARS-CoV-2 infections may have to be developed in a One Health framework and non-pharmaceutical interventions may have to consider free-roaming animals and the animal farming industry

Synthesis and characterization of a novel organic nitrate NDHP: Role of xanthine oxidoreductase-mediated nitric oxide formation

In this report, we describe the synthesis and characterization of 1,3-bis(hexyloxy)propan-2-yl nitrate (NDHP), a novel organic mono nitrate. Using purified xanthine oxidoreductase (XOR), chemiluminescence and electron paramagnetic resonance (EPR) spectroscopy, we found that XOR catalyzes nitric oxide (NO) generation from NDHP under anaerobic conditions, and that thiols are not involved or required in this process. Further mechanistic studies revealed that NDHP could be reduced to NO at both the FAD and the molybdenum sites of XOR, but that the FAD site required an unoccupied molybdenum site. Conversely, the molybdenum site was able to reduce NDHP independently of an active FAD site. Moreover, using isolated vessels in a myograph, we demonstrate that NDHP dilates pre-constricted mesenteric arteries from rats and mice. These effects were diminished when XOR was blocked using the selective inhibitor febuxostat. Finally, we demonstrate that NDHP, in contrast to glyceryl trinitrate (GTN), is not subject to development of tolerance in isolated mesenteric arteries.</p

Actividades deportivas en la naturaleza en Porto Alegre: desafíos y oportunidades

The aim of this study was to analyse the challenges and opportunities of developing outdoor sports in Porto Alegre, Brazil. Twenty-nine interviews were conducted with different stakeholders. Eight observations were conducted while participants were engaged in outdoor sports. The results indicated that selecting appropriate sites in terms of safe practice and prevention of overuse of the sites represent challenges; and the potential for the involvement of participants, instructors and local communities in the maintenance of the natural environment and in the management of outdoor sports represent opportunities. In conclusion this study demonstrated that outdoor sports must be avoided in some areas of the city. However, through proactive management and promotion of outdoor sports opportunities can mitigate the challenges.Este estudo teve por objetivo analisar os desafios e as oportunidades para o desenvolvimento de atividades esportivas na natureza em Porto Alegre, Brasil. Foram realizadas 29 entrevistas com representantes de organizações ligadas a estas atividades e oito observações de grupos de praticantes. Os resultados indicaram que a escolha de locais apropriados para a realização destas atividades e medidas para evitar a superlotação dos locais de prática, representam desafios; e o potencial de envolvimento de praticantes, instrutores e comunidades locais na manutenção do meio natural e na gestão de atividades esportivas na natureza, representam oportunidades. Em conclusão, o estudo demonstrou que existem áreas da cidade em que essas atividades devem ser evitadas. No entanto, por meio de gerenciamento proativo e promoção de atividades esportivas na natureza as oportunidades podem mitigar os desafios.El objetivo de este estudio fue analizar los desafíos y oportunidades de desarrollar actividades deportivas en la naturaleza en Porto Alegre, Brasil. Veintinueve entrevistas fueron conducidas con diferentes partes interesadas. Se realizaron ocho observaciones mientras los participantes se dedicaban a las actividades. Los resultados indicaron que la selección de sitios apropiados en términos de prácticas seguras y prevención de hacinamiento representa un desafío; y el potencial para la participación de practicantes, instructores y comunidades locales en el mantenimiento del medio ambiente natural y en la gestión de actividades deportivas en la naturaleza representa oportunidades. En conclusión, este estudio demostró que estas actividades deben evitarse en algunas áreas de la ciudad. Sin embargo, a través de una gestión proactiva y la promoción de actividades deportivas al aire libre, las oportunidades pueden mitigar los desafíos

Local parasite pressures and host genotype modulate epigenetic diversity in a mixed‐mating fish

Parasite‐mediated selection is one of the main drivers of genetic variation in natural populations. The persistence of long‐term self‐fertilization, however, challenges the notion that low genetic variation and inbreeding compromise the host's ability to respond to pathogens. DNA methylation represents a potential mechanism for generating additional adaptive variation under low genetic diversity. We compared genetic diversity (microsatellites and AFLPs), variation in DNA methylation (MS‐AFLPs), and parasite loads in three populations of Kryptolebias hermaphroditus, a predomintanly self‐fertilizing fish, to analyze the potential adaptive value of DNA methylation in relation to genetic diversity and parasite loads. We found strong genetic population structuring, as well as differences in parasite loads and methylation levels among sampling sites and selfing lineages. Globally, the interaction between parasites and inbreeding with selfing lineages influenced DNA methylation, but parasites seemed more important in determining methylation levels at the local scale

Neural-Based Ensembles and Unorganized Machines to Predict Streamflow Series from Hydroelectric Plants

Estimating future streamflows is a key step in producing electricity for countries with hydroelectric plants. Accurate predictions are particularly important due to environmental and economic impact they lead. In order to analyze the forecasting capability of models regarding monthly seasonal streamflow series, we realized an extensive investigation considering: six versions of unorganized machines—extreme learning machines (ELM) with and without regularization coefficient (RC), and echo state network (ESN) using the reservoirs from Jaeger’s and Ozturk et al., with and without RC. Additionally, we addressed the ELM as the combiner of a neural-based ensemble, an investigation not yet accomplished in such context. A comparative analysis was performed utilizing two linear approaches (autoregressive model (AR) and autoregressive and moving average model (ARMA)), four artificial neural networks (multilayer perceptron, radial basis function, Elman network, and Jordan network), and four ensembles. The tests were conducted at five hydroelectric plants, using horizons of 1, 3, 6, and 12 steps ahead. The results indicated that the unorganized machines and the ELM ensembles performed better than the linear models in all simulations. Moreover, the errors showed that the unorganized machines and the ELM-based ensembles reached the best general performances

INDIRECT ORGANOGENESIS FROM LEAF EXPLANTS AND IN VITRO SHOOTS LTIPLICATION OF Eucalyptus benthamii X Eucalyptus dunnii

Os objetivos deste trabalho foram avaliar diferentes meios de cultura na organog\ueanese indireta e na multiplica\ue7\ue3o in vitro de brotos de Eucalyptus benthamii x Eucalyptus dunnii . Para organog\ueanese, explantes foliares foram excisados no sentido transversal e cultivados in vitro, sendo os seguintes fatores testados: dois meios de cultura (MS N/2 e JADS) adicionados de 0,1 \u3bcM de ANA, duas concentra\ue7\uf5es de thidiazuron (0,1 e 0,5 \u3bcM) e presen\ue7a ou n\ue3o de PVP-40 (250 mg L-1). Ap\uf3s 70 dias de cultivo foram avaliadas as porcentagens de explantes oxidados totalmente, formando calo, produzindo antocianina, formando gema, formando brota\ue7\uf5es e o n\ufamero de brota\ue7\uf5es formadas por explante regenerando. No experimento de multiplica\ue7\ue3o, brota\ue7\uf5es isoladas foram cultivadas em meio MS, JADS e WPM, adicionados de 1,11 \u3bcM de BAP. Foram realizados quatro subcultivos a cada 28 dias e em cada subcultivo foram avaliados: a porcentagem de oxida\ue7\ue3o, de explantes apresentando clorose total ou parcial, massa fresca e n\ufamero m\ue9dio de brotos por explante. O meio de cultura MS N/2 suplementado com 0,1 \u3bcM de ANA, 0,5 \u3bcM de TDZ e PVP-40 promoveu a maior taxa de organog\ueanese (8,3%). No meio de cultura MS com 1,11 \u3bcM de BAP, a taxa de multiplica\ue7\ue3o foi maior que nos outros meios, no primeiro e segundo subcultivos (9,28 e 9,24 por m\ueas), n\ue3o havendo diferen\ue7a entre os tr\ueas meios nos demais subcultivos.The aims of this research were to evaluate different culture media for indirect organogenesis and shoot multiplication of Eucalyptus benthamii x Eucalyptus dunnii . For organogenesis, leaf explants were used to test the following treatments: two culture media (MS N/2 and JADS) supplemented with 0.1 \u3bcM 1-naphthaleneacetic acid (NAA) and thidiazuron (TDZ) (0.1 or 0.5 \u3bcM), with or without PVP- 40 (250 mg L-1). The percentage of oxidized explants, callus forming explants, explants with anthocyanin, buds, shoots and the shoot number per explant were evaluated. In the multiplication experiment, isolated shoots were cultivated in MS, JADS and WPM media, all supplemented with 1.11 \u3bcM BAP. Four subcultures were carried out every 28 days. In every subculture the explant oxidation, partial or total leaf chlorosis, fresh mass and mean number of shoot per explant were evaluated. The MS N/2 medium supplemented with 0.1 \u3bcM NAA and 0.5 \u3bcM TDZ promoted the highest rate of organogenesis (8.3%) and the culture media MS supplemented with 1.11 \u3bcM BAP the multiplication rate was higher than in the other media, in the first and the second subcultures (9.28 and 9.24, respectively), without differences between the three media in the following subcultures